I'm baffled by how the RAM in my system gets divided between Redboot and my
eCos app. The Redboot signon seems to indicate that it consumes memory from
zero upwards. Yet I'm under the impression that an eCos app is normally
linked with the code first. Since this isn't position-independent code, and
there's no memory remapping taking place, What ensures that the eCos app
doesn't try to use the same RAM as Redboot? (I'm using an EB40A ARM7 eval
board.) Is there simply some accepted start address for the eCos app that's
high enough that Redboot never bumps into it?
Also, if I build a new version of Redboot, is it important that it know
about all the RAM, or is it sufficient that it know only about enough RAM
for its own purposes? I've got some extra SRAM soldered on to the EB40A
board, and while Redboot only needs a fraction of the on-chip 256K of RAM,
I'd like my app to be able to use the left over portion of the internal RAM,
as well as the full external RAM. If I configure Redboot as though the
external RAM doesn't exist, is that a problem for the eCos app? Or does it
prevent me from, say, using Redboot to manually load an app image into that
external RAM for burning into a FIS segment?